U.S. patent number 4,323,683 [Application Number 06/119,346] was granted by the patent office on 1982-04-06 for process for making pyridinethione salts.
This patent grant is currently assigned to The Procter & Gamble Company. Invention is credited to Raymond E. Bolich, Jr., Steven A. Shaya, Christian Steuri.
United States Patent |
4,323,683 |
Bolich, Jr. , et
al. |
April 6, 1982 |
Process for making pyridinethione salts
Abstract
A process for producing heavy metal, magnesium or aluminum
pyridinethione salt crystals involving reacting a water soluble
salt of the desired metal with a water soluble pyridinethione salt
or pyridinethione itself in an aqueous surfactant medium.
Inventors: |
Bolich, Jr.; Raymond E.
(Maineville, OH), Shaya; Steven A. (Cincinnati, OH),
Steuri; Christian (Fairfield, OH) |
Assignee: |
The Procter & Gamble
Company (Cincinnati, OH)
|
Family
ID: |
22383898 |
Appl.
No.: |
06/119,346 |
Filed: |
February 7, 1980 |
Current U.S.
Class: |
546/6;
546/243 |
Current CPC
Class: |
A61K
8/02 (20130101); A61K 8/4933 (20130101); C07D
213/89 (20130101); A61Q 5/006 (20130101); A61Q
5/02 (20130101); A61K 2800/412 (20130101) |
Current International
Class: |
C07D
213/00 (20060101); C07D 213/89 (20060101); C07D
213/89 () |
Field of
Search: |
;546/6,243 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Barnett et al. Inorg. Chem 16, 1834 (1977). .
Troost, Chem. Abs. 71, 16745y (1968). .
Despotovic et al., Chem. Abs. 87, 76469b (1976). .
Blinova et al., Chem. Abs. 76, 145848m..
|
Primary Examiner: Berch; Mark L.
Attorney, Agent or Firm: Mohl; Douglas C. Gorman; John V.
Witte; Richard C.
Claims
What is claimed is:
1. A process for making heavy metal, magnesium or aluminum
N-hydroxy pyridinethione salts comprising reacting
1-hydroxy-2-pyridinethione or a water soluble salt thereof with a
water soluble heavy metal, magnesium or aluminum salt in an aqueous
surfactant medium, wherein the reaction temperature is at least
about 20.degree. C.
2. A process according to claim 1 wherein the pyridinethione
compound is an alkali metal pyridinethione salt and the
concentration of surfactant in the total reaction mixture is from
about 1% to about 24%.
3. A process according to claim 2 wherein the metal salt is a heavy
metal salt selected from the group consisting of zinc, tin, cadmium
and zirconium salts and is present in an amount sufficient to
provide a stoichiometric excess.
4. A process according to claim 3 wherein the surfactant is
anionic.
5. A process according to claim 4 wherein the heavy metal salt is a
zinc salt.
6. A process according to claim 5 wherein the reaction temperature
is from about 60.degree. C. to about 100.degree. C.
7. A process according to claim 6 wherein the concentration of
surfactant is from about 1% to about 8%.
8. A process according to claim 7 wherein the alkali metal
pyridinetione salt is sodium pyridinethione.
9. A process according to claim 8 wherein the zinc salt is zinc
sulfate.
10. A process according to claim 9 wherein the anionic surfactant
is an alkyl sulfate.
11. A process according to claim 10 wherein the alkyl sulfate is
sodium alkyl sulfate.
Description
TECHNICAL FIELD
The present invention relates to the formation of heavy metal,
magnesium or aluminum pyridinethione salts. Such salts are useful
as antidandruff agents. Up to this time the pyridinethione salts
have been in such a form that they interfered with the ability of
pearlescent materials to deliver pearlescence to compositions
containing both materials.
BACKGROUND ART
Pyridinethione salts are old as shown by U.S. Pat. No. 2,809,971,
Oct. 15, 1957 to Bernstein et al. Other patents disclosing similar
compounds and processes for making them include U.S. Pat. Nos.
2,786,847, Mar. 26, 1957 to Cislak and 3,583,999, June 8, 1971;
3,590,035, June 29, 1971; and 3,773,770, Nov. 20, 1973 all to
Damico.
While the prior art discloses pyridinethione salts and processes
for making such salts, it does not suggest forming the salts in an
aqueous surfactant medium. Furthermore, there is no suggestion that
the crystals formed in such a medium would have superior aesthetic
properties and be more compatible in a composition.
It is, therefore, an object of the present invention to provide an
improved method for making pyridinethione salt crystals.
It is a further object of the present invention to provide
pyridinethione salt crystals which are more compatible in
pearlescent cosmetic compositions.
These and other objects will become apparent from the description
of the invention which follows.
SUMMARY OF THE INVENTION
The present invention relates to the formation of heavy metal,
magnesium or aluminum pyridinethione salt crystals by reacting
pyridinethione or a water soluble pyridinethione salt with a water
soluble salt of the desired metal in an aqueous surfactant medium.
The concentration of surfactant is not critical but is preferably
from about 1% to about 24%, more preferably from about 1% to about
8%. The reaction temperature is at least about 20.degree. C.,
preferably from about 60.degree. C. to about 100.degree. C. The
crystals may be separated from the reaction medium after formation
for use in a particular formulation not containing the surfactant
used in the reaction. Alternatively, if desired, the crystals may
be left in the reaction medium for incorporation into a final
composition.
DETAILED DESCRIPTION OF THE INVENTION
The process of the present invention involves the steps enumerated
supra. The reactants can be handled in a wide variety of ways. For
example, the water soluble salt of the desired metal may be
combined with part of the surfactant and water while the remainder
of the water and surfactant are combined with pyridinethione or a
water soluble pyridinethione salt. The two mixtures are then
combined. Alternatively, all of the surfactant may be combined with
either material or put into a third container into which the
materials are then placed. All of these approaches are satisfactory
since the crystals form almost instantaneously regardless of the
approach used.
The crystals possess a median equivalent spherical diameter based
on volume, d.sub.v, and a mean sphericity ##EQU1## surface area of
spheres having an equivalent volume distribution divided by the
actual surface area of the particles as measured which makes them
more compatible with other pearlescent materials which may be
present in a composition. The median equivalent diameter is
preferably greater than 2.mu. while the mean sphericity is
preferably in the range of about 0.20 to about 0.65.
The various reaction materials are discussed in detail below.
Pyridinethione and Water Soluble Pyridinethione Salts
Pyridinethione as the term is used herein is
1-hydroxy-2-pyridinethione which has the following structural
formula in tautomeric form, the sulfur being attached to the No. 2
position in the pyridine ring. ##STR1##
The water soluble salts represent substitution of the metal cation
for the hydrogen of one of the tautomeric forms. The preferred
salts are those involving ammonium or alkali metals. Most preferred
is the sodium salt.
The amount of 1-hydroxy-2-pyridinethione or water soluble salt can
vary over a wide range (the level only dependent on the quantity of
material desired). A preferred level is from about 8% to about 16%
of the total reaction system.
Water Soluble Salt Of A Heavy Metal, Magnesium or Aluminum
Suitable metal compound reactants include salts in which the metal
may be, among others heavy metals such as, zinc, tin, cadmium and
zirconium, magnesium and aluminum. The compounds may be nitrates,
acetates, sulfates or halogens. The preferred salts are sulfates
and zinc sulfate is the most preferred. The amount of soluble metal
salt used is not critical so long as the amount is sufficient to
form the desired pyridinethione salt. The amount used therefore is
generally an amount sufficient to provide a stoichiometric excess.
An excess of about 5% is an example of a suitable excess
amount.
Surfactant
Another necessary component in the process of the present invention
is a surfactant. The term "surfactant" as used herein is intended
to denote soap and nonsoap surfactants. Any nonsoap surfactant is
suitable for use including anionic, nonionic, amphoteric, cationic
and zwitterionic types. The surfactant should be soluble in water
at the temperature of the reaction.
Examples of suitable soaps are the sodium, potassium, ammonium and
alkanol ammonium salts of higher fatty acids (those having 10-20
carbon atoms). Anionic nonsoap surfactants can be exemplified by
the alkali metal salts of organic sulfuric reaction products having
in their molecular structure an alkyl radical containing from 8-22
carbon atoms and a sulfonic acid or sulfuric acid ester radical
(included in the term alkyl is the alkyl portion of higher acyl
radicals). Preferred are the sodium, ammonium, potassium or
triethanol amine alkyl sulfates, especially those obtained by
sulfating the higher alcohols (C.sub.8 -C.sub.18 carbon atoms),
sodium coconut oil fatty acid monoglyceride sulfates and
sulfonates; sodium or potassium salts of sulfuric acid esters of
the reaction product of 1 mole of a higher fatty alcohol (e.g.,
tallow or coconut oil alcohols) and 1 to 12 moles of ethylene
oxide; sodium or potassium salts of alkyl phenol ethylene oxide
ether sulfate with 1 to 10 units of ethylene oxide per molecule and
in which the alkyl radicals contain from 8 to 12 carbon atoms,
sodium alkyl glyceryl ether sulfonates; the reaction product of
fatty acids having from 10 to 22 carbon atoms esterified with
isethionic acid and neutralized with sodium hydroxide; water
soluble salts of condensation products of fatty acids with
sarcosine; and others known in the art.
Nonionic surfactants can be broadly defined as compounds produced
by the condensation of alkylene oxide groups (hydrophilic in
nature) with an organic hydrophobic compound, which may be
aliphatic or alkyl aromatic in nature. Examples of preferred
classes of nonionic surfactants are:
1. The polyethylene oxide condensates of alkyl phenols, e.g., the
condensation products of alkyl phenols having an alkyl group
containing from about 6 to 12 carbon atoms in either a straight
chain or branched chain configuration, with ethylene oxide, the
said ethylene oxide being present in amounts equal to 10 to 60
moles of ethylene oxide per mole of alkyl phenol. The alkyl
substituent in such compounds may be derived from polymerized
propylene, diisobutylene, octane, or nonane, for example.
2. Those derived from the condensation of ethylene oxide with the
product resulting from the reaction of propylene oxide and ethylene
diamine products which may be varied in composition depending upon
the balance between the hydrophobic and hydrophilic elements which
is desired. For example, compounds containing from about 40% to
about 80% polyoxyethylene by weight and having a molecular weight
of from about 5,000 to about 11,000 resulting from the reaction of
ethylene oxide groups with a hydrophobic base constituted of the
reaction product of ethylene diamine and excess propyelene oxide,
said base having a molecular weight of the order of 2,500 to 3,000,
are satisfactory.
3. The condensation product of aliphatic alcohols having from 8 to
18 carbon atoms, in either straight chain or branched chain
configuration, with ethylene oxide, e.g., a coconut alcohol
ethylene oxide condensate having from 10 to 30 moles of ethylene
oxide per mole of coconut alcohol, the coconut alcohol fraction
having from 10 to 14 carbon atoms.
4. Long chain tertiary amine oxides corresponding to the following
general formula:
wherein R.sub.1 contains an alkyl, alkenyl or monohydroxy alkyl
radical of from about 8 to about 18 carbon atoms, from 0 to about
10 ethylene oxide moieties, and from 0 to 1 glyceryl moiety, and
R.sub.2 and R.sub.3 contain from 1 to about 3 carbon atoms and from
0 to about 1 hydroxy group, e.g., methyl, ethyl, propyl, hydroxy
ethyl, or hydroxy propyl radicals. The arrow in the formula is a
conventional representation of a semipolar bond. Examples of amine
oxides suitable for use in this invention include
dimethyldodecylamine oxide, oleyldi (2-hydroxyethyl)amine oxide,
dimethyloctylamine oxide, dimethyldecylamine oxide,
dimethyltetradecylamine oxide, 3,6,9-trioxaheptadecyldiethylamine
oxide, di)2-hydroxyethyl)-tetradecylamine oxide,
2-dodecoxyethyldimethylamine oxide,
3-dodexocy-2-hydroxypropyldi(3-hydroxypropyl)amine oxide,
dimethylhexadecylamine oxide.
5. Long chain tertiary phosphine oxides corresponding to the
following general formula:
wherein R contains an alkyl, alkenyl or monohydroxyalkyl radical
ranging from 8 to 18 carbon atoms in chain length, from 0 to about
10 ethylene oxice moieties and from 0 to 1 glyceryl moiety and R'
and R" are each alkyl or monohydroxyalkyl groups containing from 1
to 3 carbon atoms. Examples of suitable phosphine oxides are:
dodecyldimethylphosphine oxide,
tetradecyldimethylphosphine oxide,
tetradecylmethylethylphosphine oxide,
3,6,9-trioxaoctadecyldimethylphosphine oxide,
cetyldimethylphosphine oxide,
3-dodecoxy-2-hydroxypropyldi(2-hydroxyethyl)phosphine oxide,
stearyldimethylphosphine oxide,
cetylethylpropylphosphine oxide,
oleyldiethylphosphine oxide,
dodecyldiethylphosphine oxide,
tetradecyldiethylphosphine oxide,
dodecyldipropylphosphine oxide,
dodecyldi(hydroxymethyl)phosphine oxide,
dodecyldi(2-hydroxyethyl)phosphine oxide,
tetradecylmethyl-2-hydroxypropylphosphine oxide,
oleyldimethylphosphine oxide,
2-hydroxydodecyldimethylphosphine oxide.
6. Long chain dialkyl sulfoxides containing one short chain alkyl
or hydroxy alkyl radical of 1 to about 3 carbon atoms (usually
methyl) and one long hydrophobic chain which contain alkyl,
alkenyl, hydroxy alkyl, or keto alkyl radicals containing from
about 8 to about 20 carbon atoms, from 0 to about 10 ethylene oxide
moieties and from 0 to 1 glyceryl moiety. Examples include:
octadecyl methyl sulfoxide,
2-ketotridecyl methyl sulfoxide,
3,6,9-trioxaoctadecyl 2-hydroxyethyl sulfoxide, dodecyl methyl
sulfoxide,
oleyl 3-hydroxypropyl sulfoxide,
tetradecyl methyl sulfoxide,
3-methoxytridecyl methyl sulfoxide,
3-hydroxytridecyl methyl sulfoxide,
3-hydroxy-4-dodecoxybutyl methyl sulfoxide.
Zwitterionic surfactants can be exemplified by those which can be
broadly described as derivatives of aliphatic quaternary ammonium,
phosphonium, and sulfonium compounds, in which the aliphatic
radicals can be straight chain or branched, and wherein one of the
aliphatic substituents contains from about 8 to 18 carbon atoms and
one contains an anionic water-solubilizing group, e.g., carboxy,
sulfonate, sulfate, phosphate, or phosphonate. A general formula
for these compounds is: ##STR2## wherein R.sup.2 contains an alkyl,
alkenyl, or hydroxy alkyl radical of from about 8 to about 18
carbon atoms, from 0 to about 10 ethylene oxide moieties and from 0
to 1 glyceryl moiety; Y is selected from the group consisting of
nitrogen, phosphorus, and sulfur atoms; R.sup.3 is an alkyl or
monohydroxyalkyl group containing 1 to about 3 carbon atoms; X is 1
when Y is a sulfur atom and 2 when Y is a nitrogen or phosphorus
atom; R.sup.4 is an alkylene or hydroxyalkylene of from 1 to about
4 carbon atoms and Z is a radical selected from the group
consisting of carboxylate, sulfonate, sulfate, phosphonate, and
phosphate groups.
Examples include:
4-[N,N-di(2-hydroxyethyl)-N-octadecylammonio]-butane-1-carboxylate;
5-[S-3-hydroxypropyl-S-hexadecylsulfonio]-3-hydroxypentane-1-sulfate;
3-[P,P-diethyl-P-3,6,9-trioxatetradexocylphosphonio]-2-hydroxypropane-1-pho
sphate;
3-[N,N-dipropyl-N-3-dodecoxy-2-hydroxypropylammonio]-propane-1-phosphonate;
3-(N,N-dimethyl-N-hexadecylammonio)propane-1-sulfonate;
3-(N,N-dimethyl-N-hexadecylammonio)-2-hydroxypropane-1-sulfonate;
4-]N,N-di(2-hydroxyethyl)-N-(2-hydroxydodecyl)ammonio]-butane-1-carboxylate
;
3-[S-ethyl-S-(3-dodecoxy-2-hydroxypropyl)sulfonio]-propane-1-phosphate;
3-(P,P-dimethyl-P-dodecylphosphonio)-propane-1-phosphonate; and
5-[N,N-di(3-hydroxypropyl)-N-hexadecylammonio]-2-hydroxypentane-1-sulfate.
Examples of amphoteric surfactants which can be used in the process
of the present invention are those which can be broadly described
as derivatives of aliphatic secondary and tertiary amines in which
the aliphatic radical can be straight chain or branched and wherein
one of the aliphatic substituents contains from about 8 to about 18
carbon atoms and one contains an anionic water solubilizing group,
e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate.
Examples of compounds falling within this definition are sodium
3-dodecylaminopropionate, sodium 3-dodecylaminopropane sulfonate,
N-alkyltaurines such as the one prepared by reacting dodecylamine
with sodium isethionate according to the teaching of U.S. Pat. No.
2,658,072, N-higher alkyl aspartic acids such as those produced
according to the teaching of U.S. Pat. No. 2,438,091, and the
products sold under the trade name "Miranol" and described in U.S.
Pat. No. 2,528,378.
Many cationic surfactants are known to the art. By way of example,
the following may be mentioned:
dodecyltrimethylammonium chloride;
nonylbenzylethyldimethylammonium nitrate;
tetradecylpyridinium bromide;
laurylpyridinium chloride;
cetylpyridinium chloride;
laurylpyridinium chloride;
laurylisoquinolium bromide;
dilauryldimethylammonium chloride; and
stearalkonium chloride.
Many additional nonsoap surfactants are described in McCUTCHEON'S,
DETERGENTS AND EMULSIFIERS, 1979 ANNUAL, published by Allured
Publishing Corporation, which is incorporated herein by
reference.
The above-mentioned surfactants can be used alone or in combination
in the process of the present invention. The surfactant
concentration, as noted earlier, is not critical but is preferably
from about 1% to about 24%, more preferably from about 1% to about
8%.
Reaction Temperature
The reaction temperature should be above about 20.degree. C.,
preferably from about 60.degree. C. to about 100.degree. C. The
temperature can be achieved and maintained through the use of any
of the techniques well known in the art.
Reactant Medium
The process of the present invention is carried out in an aqueous
medium wherein water is the major diluent.
Industrial Applicability
The pyridinethione salts made in accordance with the present
process are useful in hair care compositions as antidandruff
agents.
The following Examples further describe and demonstrate the
preferred embodiments within the scope of the present invention.
The Examples are given solely for the purpose of illustration and
are not to be construed as limitations of the present invention as
many variations thereof are possible without departing from its
spirit and scope. Unless otherwise indicated, all percentages
herein are by weight.
EXAMPLE I
Zinc pyridinethione salt crystals of the present invention were
made using the following procedure.
A first mixture was prepared by combining 14.7 parts of zinc
sulfate, 21.7 parts of a 29% aqueous solution of sodium alkyl
sulfate and 8.6 parts of water in a mix tank. This mixture was
heated to 95.degree. C.
A second mixture was prepared by combining 35 parts of a 40%
aqueous solution of sodium pyridinethione with 20 parts of a 29%
aqueous solution of sodium alkyl sulfate in a mix tank. This second
mixture was also heated to 95.degree. C.
The first mixture was added to the second mixture resulting in the
formation of zinc pyridinethione crystals which were washed and
collected.
The total batch size, the combined mixtures, was 2500 grams.
EXAMPLE II
The crystals of zinc pyridinethione made according to Example I
were evaluated to determine their particle size and sphericity.
The median equivalent spherical diameter based on volume (particle
size) was determined by means of a SediGraph 5000 D Particle Size
Analyzer supplied by Micrometrics Instrument Corporation.
The SediGraph 5000 D determines, by means of X-ray absorption, the
concentration of particles remaining at decreasing sedimentation
depths as a function of time. Stokes' Law relates the measured
equilibrium velocity of a particle falling through a viscous medium
to its equivalent spherical diameter (ESD). ##EQU2## .eta.=liquid
viscosity .nu.=equilibrium velocity
.rho..sub.o =liquid density
g=gravitational acceleration
.rho.=particle density
.nu. is determined from the Sedigraph while the other variables are
available from reference sources or obtained experimentally. In the
present analysis water was the liquid and the liquid viscosity was
0.76 cp.
The density of zinc pyridinethione particles is known to be about
1.81 g/cc, (Barnett, B. L., et al, "Structural Characterization of
Bis-(N-oxypyridine-2-thionato) Zinc (II)", Inorganic Chemistry 16,
1834, [1977]), incorporated herein by reference.
The median equivalent spherical diameter based on volume (d.sub.v)
of the crystals was determined to be 5.4.mu.. This median
equivalent spherical diameter was taken from the mass distribution
of particles described in 1. below. The determination of a specific
surface area based on equivalent spherical diameters was as
follows:
1. A cumulative mass distribution of equivalent spherical diameters
in .mu.m was obtained using the SediGraph instrument described
previously. The rate for the instrument was 866 and the starting
diameter of 100 .mu.m.
2. The cumulative mass distribution was divided into equal
logarithmic intervals in .mu.m. The sizes of the intervals are
shown in the following table.
3. The cumulative mass distribution at each equal logarithmic
interval was determined.
4. The diameter at the centerpoint of each interval was
determined.
5. The value of the cumulative mass percent distribution at the
centerpoints of the intervals was determined.
6. The value of the differential mass percent distribution was then
determined.
7. The amount of material for each interval was determined,
assuming that there was a total of one gram which was evaluated.
These values are the values in 6, above, divided by 100.
8. The assumed spherical particle surface area of the material
contained in each interval was calculated using diameters equal to
the centerpoints of the intervals. Therefore, the calculation for a
particular interval, i, is ##EQU3##
All of the above data are shown in the following table. The
numerical column headings correspond to the numbers above.
______________________________________ 2 3 4 5 6 7 8
______________________________________ 1.59 0. 1.78 0.5 0.5 0.005
0.009 2.00 1.0 2.28 2.5 2.0 0.020 0.029 2.52 4.0 2.87 7.0 4.5 0.045
0.052 3.17 10.0 3.59 16.0 9.0 0.090 0.083 4.00 22.0 4.52 32.0 16.0
0.160 0.118 5.04 42.0 5.70 55.0 23.0 0.230 0.134 6.35 68.0 7.18
76.0 21.0 0.210 0.097 8.00 84.0 9.04 88.5 12.5 0.125 0.046 10.08
93.0 11.4 95.0 6.5 0.065 0.019 12.7 97.0 14.4 98.0 3.0 0.030 0.007
16.0 99.0 18.1 99.5 1.5 0.015 0.003 20.2 100.0 22.8 100.0 0.5 0.005
0.001 25.4 100.0 TOTAL 100.0 1.000 g 0.598 m.sup.2 /g
______________________________________
The actual specific surface area for the crystals was determined by
means of a B.E.T. surface area analysis using nitrogen gas. The
B.E.T. analysis showed the crystals to have a specific surface area
of 2.39 m.sup.2 /g.
The sphericity was then determined as follows: ##EQU4##
EXAMPLE III
Zinc pyridinethione salt crystals were made using the following
process of the present invention.
A first mixture was prepared by combining 7.3 parts of a 28%
aqueous solution of ammonium alkyl sulfate, 2 parts of zinc sulfate
and 40.7 parts of water in one mix tank. The mixture was heated to
80.degree. C.
A second mixture was prepared by combining 7.3 parts of a 28%
aqueous solution of ammonium alkyl sulfate, 5 parts of a 40%
aqueous solution of sodium pyridinethione and 37.7 parts of water
in another mix tank. This mixture was also heated to 80.degree.
C.
The first and second mixtures were metered into a third tank at the
rate of 1 kg./min. The resulting zinc pyridinethione crystals were
washed and stored.
* * * * *